1. Field of the Invention
The present invention relates to a photosensitive compound and a photosensitive composition including the same, and more particularly, to a photosensitive compound that may improve a solubility performance of an exposed portion while preventing a loss of an unexposed portion, thereby improving a pattern perpendicularity in a semiconductor photolithography process, and to a photosensitive composition including the photosensitive compound.
2. Description of the Related Art
In general, sulfonic ester may be used as a photosensitive material from among compositions used in a lithography process utilizing visible rays, ultraviolet rays, electron beams, ion beams, and x-rays.
A photosensitive composition may be prepared by dissolving the sulfonic ester and a resin capable of being dissolved in a basic aqueous solution in a solvent. The photosensitive composition may be heated to about 50° C. to 150° C. after being coated on a film, so that a residual solvent is easily eliminated. The film generated after the heating may be exposed using an exposurer, and developed using a developer to thereby obtain a desired pattern. In this instance, the sulfonic ester exposed in the ultraviolet rays may be transformed into a carboxylic acid more readily dissolved in a basic developer. In this manner, the desired pattern may be obtained using a development speed difference between an exposed portion and an unexposed portion.
The sulfonic ester may be diversely provided along with a complexity in a semiconductor process and a need for various thicknesses of a film. However, in an existing sulfonic ester, a residual not being dissolved in a developer may be generated on a bottom of a substrate when the thickness of the film is relatively great. When the sulfonic ester having an excellent affinity for the developer is used in order to remove the residual, large areas of the unexposed portion may be lost. Also, when the development speed is reduced in order to prevent a film loss occurring in the unexposed portion, greater exposure energy may be needed.